The present invention relates to a method of manufacturing a hidden type shoe with a replaceable vamp and strap and particularly a shoe that has a replaceable vamp and strap movably fastened to female latch members which have a latch strut encased in the outsole to form a neat appearance without jamming during foaming to facilitate vamp and strap replacement operation.
Conventional methods of manufacturing shoes with replacing vamp and strap (such as the one shown in FIGS. 1 and 2) generally include forming an outsole 1. When making the outsole 1, a plurality of female latch members 2 are disposed in advance in an upper mold. A lower mold having a cavity is filled with foaming material. Then the upper mold and lower mold are coupled together to proceed blowing and foaming process to form the outsole 1. The female latch members 2 are embedded in the outsole 1 at the selected peripheral locations. Each female latch member 2 has an insert hole 3 formed on the top surface to receive and engage with a male latch member 4. The male latch member 4 is engaged with fastening lugs located at two sides of the vamp 5 or at a lower side of the strap 6. The insert hole 3 is bordered by a side wall which has a round aperture 7. Inside the insert hole 3, there is an elastic teeth flap 8 engageable with a teeth section located at the lower portion of the male latch member 4. Thus the male latch member 4 and female latch member 2 may be engaged to fasten the vamp 5 or strap 6 to the outsole 1. The vamp 5 or strap 6 also may be detached from the outsole 1 for replacement. The outer rim of the outsole 1 further has an opening 9 matching the round aperture 7 of the female latch member 2. A pushbutton 91 may be inserted in the opening 9 with one end to depress the elastic teeth flap 8 for disengaging the male latch member 4 from the female latch member to replace the vamp 5 or strap 6.
The manufacturing method set forth above is quite complicated. The forming of the opening 9 in the outer rim of the outsole 1 is especially troublesome. As the opening 9 must be matched to the round aperture 7, precise alignment is difficult. To prevent the pushbutton 91 from slipping out of the female latch member 2 after held in the round aperture 7, the pushbutton 91 must have a jutting ring 92 at the inner end to engage with the inner peripheral rim of the round aperture 7. Moreover, the pushbutton 91 also has an outer end exposed outside the opening 9 to allow people to depress with fingers. The outer end has to couple with a soft cap 93 for depressing use. Because of the jutting ring 92 at the inner end, the cap 93 cannot be integrally made with the pushbutton 91 due to molding process constraint. All this adds manufacturing difficulty and increase production cost. The resulting products also are not sightly and do not have much appealing.
The primary object of the invention to provide a method of manufacturing a hidden type shoe with a replaceable vamp. In the manufacturing process, an elastic shrouding membrane is disposed on the juncture of a latch strut and a jutting ring to effectively prevent foaming material from sticking to latch strut and allow the latch strut to be hidden inside the periphery of the outsole to become more sightly. The manufacturing method also offers a simpler process to reduce cost.
To attain the foregoing object, the method according to the invention mainly includes a plurality of seal elements disposed in advance on a lower side of an upper mold of the shoe. The seal element has a plate located on the top side thereof and an insert blade located on a lower side and are interposed by a rectangular seal block therebetween. The seal element is matched in advance with a female latch member before the upper mold is coupled with a lower mold. Then a foaming material is blowing inside the molds to form an outsole with a sole rim formed on the periphery thereof. The female latch member is embedded in the outsole and has a vertical insert opening with an elastic teeth flap located therein. The insert opening is bordered by an outer sidewall which has a jutting ring formed thereon. The jutting ring has an annular indented neck and a through hole formed in the center thereof communicating with the insert opening for housing a latch strut. The latch strut has an outer end formed a cap end. Before the upper and lower molds are coupled, the cap end and the jutting ring are covered by a resilient shrouding membrane so that foaming material won""t stick to the latch strut and cap end during foaming and blowing processes. The cap end further may be located close to the outer periphery of the outsole for user to depress the elastic teeth flap in the female latch member for disengaging male latch members located at the lower sides of the vamp or strap thereby to facilitate replacement of the vamp and strap.